Lubricating oil composition



aftented Get. 24, 1e

2,361,352 LUBRICATING on. comosrrron Ferdinand P. Otto, Woodbury, N. 5., assignor to Socony-Vacuum Oil Company, Incorporated, New York, N. Y., a corporation of New York No Drawing. Application December 11, 1941,

Serial No. 422,518

.13 Claims. (01.252-48) This invention has to do with the treatment of hydrocarbon products such as mineral oils to improve their characteristics, and more specifically to the addition to petroleum lubricating oils of characterizing agents which improve their ability to resist the deteriorating efi'ect of oxidation'and their ability to lubricate bearing surfaces which are subjected to extreme pressures such as are now commonly encountered in hypoid gears and the like.

rosive to the metals which they encounter in use,

as, for example, bearing metals in automotive use. It has now been found that stabilization of these oils against suchoxidation efiects may be conveniently accomplished by addition to the oils of certain materials which substantially retard the oxidation of the oils, whether or not metal is present, or by the addition of certain other materials which apparently have the ability to inhibit the catalytic effect of metals in promoting oxidation reactions and thus prevent the formation of sludge and/or acidic constituents and the like under normal conditions of use and achieve an equally good practical result, although materials of the latter class may be incapable of inhibiting oxidation of oils in the absence of metals. This invention has to do with stabilizing reaction products which appear to be of this latter class, not heretoforeknown to be effective for this purpose, and with oils stabilized by the use of these reaction products. Recent changes in automotive engine design, tending toward higher bearing pressures, higher rotative speeds, higher engine temperatures, etc., have been concurrentwith marked advances in methods of refining lubricant oils for automotive use, The demand for'oils having lesser changes in viscosity with temperature change, that is, higher viscosity index, commonly referred to as V. 1., has been met by refining lubricants intended for motor oils by certain sqlvent refining or solvent extraction processes. reagents possess solvent power for hydrocarbons "of various types; as, for example, dichlorodiethyl ether, cresylic acid, phenol, chloraniline, chlorophenol, phenetidine, benzyl alcohol, nitrobenzene, benzonitrile, furfural, aniline, benzylacetate, liquid sulphur dioxide, mixtures of liquid sulphur dioxide or aniline with benzol, and the like. Those solvent refining processes are designed to Certain liquid concentrate in the desired lubricant fraction those compounds of a "parafilnic nature possessed of the ability to suffer only a small change of viscosity, with changes of temperature, and to reject the compounds of "naphthenic" nature which do sufier such change of viscosity to such a marked degree. These refining processes have provided a supply of an oil of quite desirable general characteristics definitely far'superior to any oil previously produced from mixed base or asphaltic crudes, and superior to a like, though lesser, degree over oils previously produced from paraflln base crudes.

It has been found that the solvent refined motor oils referred to above are definitely corrosive to the newer bearing metals referred to above under normal conditions of automotive use, due to oxidation during use, sometimes resulting in bearing failure after only a few thousand miles of normal driving. It is further known the V. I. of the lubricating oil, the more pro- I nounced is the tendency to corrosion of the kind referred to above. Generally speaking, the problem is encountered in oils having a V. I. or 75 or higher, and becomes pronounced in oils hav so ing a V. I. of 80 to 85 or higher, and very pro.-

nounced in oils of V. I. or higher.

Furthermore, the present trend in automotive design toward lower body styles, rapid acceleration, andthe use of hypoid gears has increased the unit loadings on rear axles. In some cases the unit pressures encountered become great enough to rupture the oil film of ordinary mineral oil lubricants, with consequent metal to metal contact. In other lines of power transmission and the like, there is a similar tendency toward the use of high unit which are near or beyon the limit at which mineral oils, alone, will maintain efifective lubrication. The'present invention is, therefore, specifically concerned with the production of lubricants capable of withstanding the high unit loadings which occur in such instances. Such lubricants are generally referred to as extreme pressure agents. L

Lubricants of the extreme pressure type are normally produced by adding to a hydr arbon lubricating oil a small amount of some ch acterizing substance which enables it to maintain alubricant film unruptured under conditions which would cause the-breakdown of a film formed of ressures of a degree oil alone. -Such additive substances are spoken of as E. P. (extreme pressure) bases, or E. P. ingredients. Many commonly used E. P. bases are composed of sulphur dissolved in mineral oil, sulphurized vegetable or animal oils, chlorinated compounds, metallic soaps, and the like. This invention is specifically concerned with the use, as E. P. characterizing ingredients, of reaction products new and novel for the purpose, and not hithertofore so used or known to be useful for this purpose.

It is an object of this invention to provide an extreme pressure lubricant. together with a base for use in compounding same, whichdubricant is superior to lubricants of this class heretofore commonly known, particularly in load-carrying capacity, stability, and maintenance of extreme pressure lubricating properties under sustained conditions of high loading. It is an object of this invention to prepare novel and valuable ingredients and to combine them with hydrocarbon lubricant oils to produce lubricants having high load bearing capacities, to prepare such ingredients which have good characteristics of stability,

and which are less corrosiv than ordinary extreme pressure ingredients. Further objects are the provision of methods of preparing lubricants containing these novel characterizing ingredients and methods of lubrication making use of the lubricants so produced. 7

It is an important object of this invention to provide means for satisfactorily inhibiting or preventing corrosion from taking place toa serious degree particularly in oils of relatively high viscosity index. It is also an object of this invention to provide a substantially non-corrosive motor oil of high V. I. Still another object of themvention is to provide an additive reagent or ingredient capable of inhibiting the corrosive properties of these oils. The production of solvent refined oils of low corrosive properties under conditions of automotive use is a major object of this invention, aswell as the method of production of such oils which combine a relatively high viscosity index with a relatively low tendency to produce such corrosion.

A further object is the provision of a method of lubrication making use of oils containing these novel ingredients.

The present invention is predicated upon the discovery that hydrocarbon oils of the classes defined above can be stabilized against the formation of acidic and/or corrosive bodies by oxidation in the presence of metals by the addition to said oils of a relatively-small amount of the reaction products of cardanol ethers and halides of sulphur. The present invention is also predicated upon the discovery that novel lubricants having exceptional extreme pressure lubricating characteristics can be produced by adding to oil a.

'sufllcient quantity of these same materials. The

aforesaid nov'el reaction products shall hereinafter be referred to as halo-sulphurized cardanol ethers, or halo-sulphurized cardanyl ethers.

The term cardanyl as used herein describes that group or radical which remains on the removal of the OH radical from cardanol, as

Making use'of this term, the following structural formula represents cardanyl ethyl ether,

It is believed that sulphur mono-and di-halides react with the carbon atoms of the unsaturated bond of the C14H27 group resulting in the formation of the sulpho-halogenated product.

The foregoing suggestion for the mechanism of reaction of sulphur halides and cardanol ethers is merely speculation and is not to be interpreted strictly so as to limit in any way the scopeof this invention, for the halo-sulphurized cardanol ethers herein described are contemplated broadly as the reaction products of sulphur halides/and cardanol ethers.

Typical halo-sulphurized cardanol ethers were prepared as follows:

(a) Cardanyl ethyl ether-sulphur monochloride reaction product A solution of 21.4 grams of sulphur monochloride dissolved in 20 cc. of benzol is gradually added (b) Cardanyl ethyl ether-sulphur dichloride reaction product To a stirred benzol solution of cardanyl ethyl ether are gradually added 24.5 grams of sulphur dichloride. The temperature is maintained at approximate y 30 C. during this addition which requires about one and one-half hours. The mixture is then stirred at room temperature for three hours, followed by refluxing at approximately 78 C. for three hours more. water-washing until the washings are neutral. Then, the solution is topped under diminished pressure to 175- C. to remove the solvent and to obtain the finished product. The reaction product, a brown viscous oil, contains about 6.4% sulphur and about 6.4% chlorine.

formula of (32011120, and probable structural formula of H:1C14.C0H4.OH with one'"unsaturated bond in the Hr'zCmradical, which is meta to the OH radical. The ethers of cardanol contemplated herein are those in which the hydrogen of the -OH radical has been replaced by an or-. I

In preparing the finished hydrocarbon oil composition in accordance with our invention the aforesaid reaction products are intimately incorporated with or dissolved in the oil which is to be stabilized against the accelerating action of metals on the deteriorating effects of oxidation reactions -and against its normal tendency to corrode metal bearings, etc'., and the product thus obtained may then' be employed for the purposes This is followed by assists and uses for which the unstabilized oil itself is normally employed, but with the improved results above described.

The reaction products, asproduced and described, are also novel extreme pressureingre-- dients, and when small amounts are added to or directly dissolved in a proper hydrocarbon lubricating oil, confer upon it a greatly enhanced ability to maintain lubrication under extreme conditions of loading.

To demonstrate the effectiveness of such reaction products under actual operating conditions of an automotive engine, unblended oils and improved oils, containing the reaction products, were subjected to the Lauson engine test. The tests were carried out in a single-cylinder Lauson engine operated continuously over a time interval of 16 hours with the cooling medium held at a temperature of about 212 F. and the oil temperature held at about 280 F. The engine was operated at a speed of about 1830 R. P. M. At the end of each test the oil was tested for acidity (N. N.) and viscosity.

The following data obtained by Lauson engine tests indicate clearly the emcacy of the halo-sulphurized car'danol ethers in retarding acid formation and in retarding changes in viscosity with temperature change. This data is shown in Table I wherein the blank oil is a solvent refined oil of Saybolt Universal viscosity of 45 secs. at 210 F.

Table .I

s. U. v. Kin. vise. Additive N. N. F. 210 F.

None.-. a saw as 2% cardanyi etb l ethersulphur mon oride react on product 0. 7 46. 76 29 1 2'|;70noa.8. i .i..1.--.fi1.--. 1. 7 46.86 6.82

e y e erulphur dichloride reaction product 0.4 45.03 5.00

As hereinbefors mentioned, the novel reaction products contemplated herein are eiiective extreme pressure (E. R) agents. 011 blends containing the typical halo-sulphurized cardanol ethers prepared above were subjected to the Almen pin test (described by Wolf and Mongey. Free. A. P. I., 1932, pp4 118-130) and the S. A. E. test (described Anon. S. A. E. Journal 30, 23-4, 1936) with the results as shown in TableII.

The oil used in the Almenpin and s. a. n.- tests was a mineral oil of 80-90 seconds Saybolt Universal viscosity at 210 F.

Itwill be observed that extreme pressure lubricants embodying this invention are exceptionally effective.

The proportion of the characterizing agents of this invention used in admixture with ordinary hydrocarbon lubricant oil to provide an extreme pressure lubricant may be varied. Sugg limits from about 0.25% to about 20% are those which will convert ordinary hydrocarbon lubricants to extreme pressure lubricants capable of withstandingthe conditions of use now imposed. Within this range, it is preferable with all re 5 action products ofmately per cent. The recommended concentration oi the novel reaction products of this invention for the purpose of preventing acid formation and viscosity change in temperature is from about 0.25% to about 5% by weight in oil, with concentrations of the order of 2 per cent. being preferred. Thus, depending upon the oil and the results desired, the reaction products contemplated herein may be used in amounts r from about 0.25% to about per cent. It will be understood further that'the present invention is not restricted to the details of the above examples which aregiven merely as illustrations of this invention, but that various 20 changes may be made in these details without departing from the true scope of this invention ,as defined in the appended claims.

I claim: 1. A lubricant comprising a hydrocarbon oil and a small proportion of a sulphurand halogen-containing reaction. product obtained by reaction of a cardanol ether and a sulphur halide.

2. A lubricating oil composition comprising a relatively large proportion of a lubricating oil which normally tends to rupture at the surface of contact with a bearing metal under relatively I high bearing pressure and in admixture therewith a relatively small amount, sumcient to' prevent such rupture, of the sulphurand halogen-containing reaction product of a cardanol ether and a sulphur halide.

3. A lubricating oil composition comprising a relatively large proportion of a lubricating oil which tends to rupture at the surface of contact with a bearing metal under relatively high bearing pressure and in admixture therewith a relatively small amount, sumcient to prevent such rupture, of the sulphurand chloriness containing reaction product of a cardanol ether and sulphur monochloride.

s. A lubricating oil composition comprising a relatively large proportion of a lubricating oil which normally tends to rupture at the surface .5 of contact with a bearing metal under relatively high bearing pressure and in admixture therewith a relatively small amount, sumclent to prevent such rupture, of the sulphurand chlorinecontg reaction product of a cardanol ether and sulphur dichloride.

'5. A lubricating oil composition comprising a relatively large proportion of a lubricating oil which normally tends to rupture at the surface of contact with a bearing metal under. relatively to high bearing pressure and in admixture there- I with a relatively small amount, sufllcient to prevent suchrupture, of the sulphurand chlorinecontaining reaction product of a cardanyl alhl ether and a sulphur halide.

6. A lubricating oil composition, comprising a relatively large proportion of a lubricating oil which normally-tends to rupture at the surface of; contact with a bearing metal under relatively vhigh bearing pressure and in admixture therewith a relatively small amount, sufflcient to prevent such rupture, of the sulphurand chlorinecontaining reaction product of a cardanyl aim! ether and sulphur monochloride.

7. A lubricating oil composition compg a is relatively large proportion of a lubricating oil this class to use approme which normally tends to rupture at the surface of contact with a bearing metal under relatively high bearing pressure and in admixture therewith a relatively small amount, suflicient to prevent such rupture, of the sulphurand chlorinecontaining reaction product of a cardanyl alkyl ether and sulphur dichloride.

8. A lubricating oil composition comprising a relatively large proportion of a lubricating oil which normally tends to rupture at the surface of contact with a bearing metal under relatively high bearing pressure and in admixture therewith a relatively small amount, suflicient to prevent such rupture, of the sulphurand halogencontaining reaction product of cardanyl ethyl ether and a sulphur halide.

9. A lubricating oil composition comprising a relatively large proportion of a lubricating oil which normally tends to rupture at the surface of contact with a bearing metal under relatively high pressure and in admixture therewith a relatively small amount, sufiicient to prevent such rupture, of the sulphurand chlorine-containing reaction product of cardanyl ethyl ether and sulphur monochloride.

10. A lubricating oil composition'comprising a relatively large proportion of a lubricating oil which normally tends to rupture at the surface of contact with a bearing metal under' relatively high pressure and in admixture therewith a relatively small amount, suflicient to prevent such rupture, of the sulphurand chlorine-containing reaction product of cardanyl ethyl ether and sulphur' dichloride.

11. The method of lubricating relatively moving metal parts wherein unit bearing pressures of high magnitude are developed, which comprises applying to the area of contact between said parts a mixture of viscous petroleum oil and asmall proportion, suflicient to increase the load carrying capacity of the mixture, of the sulphurand halogen-containing reaction product of a cardanol ether and a sulphur halide.

12. A lubricating oil composition comprising a relatively large proportion of a lubricating oil of the type normally tending to deteriorate by oxidation under normal conditions of use involving the accelerating action of metals and in intimate admixture therewith a relatively small proportion, suflicient to inhibit such deterioration, of the sulphurand chlorine-containing reaction product of a cardanol ether and a sulphur halide, said composition being further characterized by a relatively high stability toward viscosity change with temperature change under normal conditions of use.

13. A lubricant comprising a hydrocarbon oil and a small proportion of a sulphurand halogen-containing reaction product obtained by reaction of a cardanol ether and a sulphur halide,

said reaction product being present in an amount of from about 0.25% to about 20 per cent.

FERDINAND P. OTTO. 

